net.sf.saxon.event

## Class TreeReceiver

- java.lang.Object
- - net.sf.saxon.event.SequenceReceiver
  - - net.sf.saxon.event.TreeReceiver

- All Implemented Interfaces:
    Result, Receiver

      public class TreeReceiver
      extends SequenceReceiver

  A TreeReceiver acts as a bridge between a SequenceReceiver, which can receive events for constructing any kind of sequence, and an ordinary Receiver, which only handles events relating to the building of trees. To do this, it has to process any items added to the sequence using the append() interface; all other events are passed through unchanged.

  If atomic items are appended to the sequence, then adjacent atomic items are turned in to a text node by converting them to strings and adding a single space as a separator.

  If a document node is appended to the sequence, then the document node is ignored and its children are appended to the sequence.

  If any other node is appended to the sequence, then it is pushed to the result as a sequence of Receiver events, which may involve walking recursively through the contents of a tree.

- - ### Field Summary

    - ### Fields inherited from class net.sf.saxon.event.SequenceReceiver

      `pipelineConfiguration, previousAtomic, systemId`

    - ### Fields inherited from interface javax.xml.transform.Result

      `PI_DISABLE_OUTPUT_ESCAPING, PI_ENABLE_OUTPUT_ESCAPING`

  - ### Constructor Summary

    Constructors
    Constructor and Description
    `TreeReceiver(Receiver nextInChain)` Create a TreeReceiver

  - ### Method Summary

    Methods
    Modifier and Type | Method and Description
    --- | ---
    `void` | `append(Item item, int locationId, int copyNamespaces)` Append an arbitrary item (node or atomic value) to the output
    `void` | `attribute(NodeName nameCode, SimpleType typeCode, CharSequence value, int locationId, int properties)` Notify an attribute.
    `void` | `characters(CharSequence chars, int locationId, int properties)` Character data
    `void` | `close()` End of event sequence
    `void` | `comment(CharSequence chars, int locationId, int properties)` Output a comment
    `void` | `endDocument()` Notify the end of a document node
    `void` | `endElement()` End of element
    `Receiver` | `getUnderlyingReceiver()` Get the underlying Receiver (that is, the next one in the pipeline)
    `void` | `namespace(NamespaceBinding namespaceBinding, int properties)` Notify a namespace.
    `void` | `open()` Start of event sequence
    `void` | `processingInstruction(String target, CharSequence data, int locationId, int properties)` Processing Instruction
    `void` | `setPipelineConfiguration(PipelineConfiguration pipe)` Set the pipeline configuration
    `void` | `setSystemId(String systemId)` Set the system ID
    `void` | `setUnparsedEntity(String name, String uri, String publicId)` Set the URI for an unparsed entity in the document.
    `void` | `startContent()` Notify the start of the content, that is, the completion of all attributes and namespaces.
    `void` | `startDocument(int properties)` Start of a document node.
    `void` | `startElement(NodeName nameCode, SchemaType typeCode, int locationId, int properties)` Notify the start of an element
    `boolean` | `usesTypeAnnotations()` Ask whether this Receiver (or the downstream pipeline) makes any use of the type annotations supplied on element and attribute events

    - ### Methods inherited from class net.sf.saxon.event.SequenceReceiver

      `append, getConfiguration, getNamePool, getPipelineConfiguration, getSystemId`

    - ### Methods inherited from class java.lang.Object

      `clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait`

- - ### Constructor Detail

    - #### TreeReceiver

          public TreeReceiver(Receiver nextInChain)

      Create a TreeReceiver
      Parameters:
        `nextInChain` - the receiver to which events will be directed, after expanding append events into more primitive tree-based events

  - ### Method Detail

    - #### setSystemId

          public void setSystemId(String systemId)

      Description copied from class: `SequenceReceiver`
      Set the system ID
      Specified by:
        `setSystemId` in interface `Result`
      Specified by:
        `setSystemId` in interface `Receiver`
      Overrides:
        `setSystemId` in class `SequenceReceiver`
      Parameters:
        `systemId` - the URI used to identify the tree being passed across this interface

    - #### setPipelineConfiguration

          public void setPipelineConfiguration(PipelineConfiguration pipe)

      Description copied from interface: `Receiver`
      Set the pipeline configuration
      Specified by:
        `setPipelineConfiguration` in interface `Receiver`
      Overrides:
        `setPipelineConfiguration` in class `SequenceReceiver`
      Parameters:
        `pipe` - the pipeline configuration

    - #### getUnderlyingReceiver

          public Receiver getUnderlyingReceiver()

      Get the underlying Receiver (that is, the next one in the pipeline)
      Returns:
        the underlying Receiver

    - #### open

          public void open()
                    throws XPathException

      Start of event sequence
      Specified by:
        `open` in interface `Receiver`
      Overrides:
        `open` in class `SequenceReceiver`
      Throws:
        `XPathException` - if an error occurs

    - #### close

          public void close()
                     throws XPathException

      End of event sequence
      Throws:
        `XPathException` - if an error occurs

    - #### startDocument

          public void startDocument(int properties)
                             throws XPathException

      Start of a document node.
      Parameters:
        `properties` - bit-significant integer indicating properties of the document node. The definitions of the bits are in class `ReceiverOptions`
      Throws:
        `XPathException` - if an error occurs

    - #### endDocument

          public void endDocument()
                           throws XPathException

      Notify the end of a document node
      Throws:
        `XPathException` - if an error occurs

    - #### startElement

          public void startElement(NodeName nameCode,
                          SchemaType typeCode,
                          int locationId,
                          int properties)
                            throws XPathException

      Notify the start of an element
      Parameters:
        `nameCode` - integer code identifying the name of the element within the name pool.
        `typeCode` - integer code identifying the element's type within the name pool.
        `properties` - bit-significant properties of the element node
        `locationId` - an integer which can be interpreted using a `LocationProvider` to return information such as line number and system ID. If no location information is available, the value zero is supplied.
      Throws:
        `XPathException` - if an error occurs

    - #### namespace

          public void namespace(NamespaceBinding namespaceBinding,
                       int properties)
                         throws XPathException

      Notify a namespace. Namespaces are notified after the startElement event, and before any children for the element. The namespaces that are reported are only required to include those that are different from the parent element; however, duplicates may be reported. A namespace must not conflict with any namespaces already used for element or attribute names.
      Parameters:
        `namespaceBinding` - the prefix/uri pair
        `properties` - The most important property is REJECT_DUPLICATES. If this property is set, the namespace declaration will be rejected if it conflicts with a previous declaration of the same prefix. If the property is not set, the namespace declaration will be ignored if it conflicts with a previous declaration. This reflects the fact that when copying a tree, namespaces for child elements are emitted before the namespaces of their parent element. Unfortunately this conflicts with the XSLT rule for complex content construction, where the recovery action in the event of conflicts is to take the namespace that comes last. XSLT therefore doesn't recover from this error:
      Throws:
        `IllegalStateException:` - attempt to output a namespace when there is no open element start tag
        `XPathException` - if an error occurs

    - #### attribute

          public void attribute(NodeName nameCode,
                       SimpleType typeCode,
                       CharSequence value,
                       int locationId,
                       int properties)
                         throws XPathException

      Notify an attribute. Attributes are notified after the startElement event, and before any children. Namespaces and attributes may be intermingled.
      Parameters:
        `nameCode` - The name of the attribute, as held in the name pool
        `typeCode` - The type of the attribute, as held in the name pool
        `properties` - Bit significant value. The following bits are defined:
        DISABLE_ESCAPING
      Disable escaping for this attribute
        NO_SPECIAL_CHARACTERS
      Attribute value contains no special characters
        `value` - the string value of the attribute
        `locationId` - an integer which can be interpreted using a `LocationProvider` to return information such as line number and system ID. If no location information is available, the value zero is supplied.
      Throws:
        `IllegalStateException:` - attempt to output an attribute when there is no open element start tag
        `XPathException` - if an error occurs

    - #### startContent

          public void startContent()
                            throws XPathException

      Notify the start of the content, that is, the completion of all attributes and namespaces. Note that the initial receiver of output from XSLT instructions will not receive this event, it has to detect it itself. Note that this event is reported for every element even if it has no attributes, no namespaces, and no content.
      Throws:
        `XPathException` - if an error occurs

    - #### endElement

          public void endElement()
                          throws XPathException

      End of element
      Throws:
        `XPathException` - if an error occurs

    - #### characters

          public void characters(CharSequence chars,
                        int locationId,
                        int properties)
                          throws XPathException

      Character data
      Parameters:
        `chars` - The characters
        `locationId` - an integer which can be interpreted using a `LocationProvider` to return information such as line number and system ID. If no location information is available, the value zero is supplied.
        `properties` - Bit significant value. The following bits are defined:
      DISABLE_ESCAPING
        Disable escaping for this text node
      USE_CDATA
        Output as a CDATA section
      Throws:
        `XPathException` - if an error occurs

    - #### processingInstruction

          public void processingInstruction(String target,
                                   CharSequence data,
                                   int locationId,
                                   int properties)
                                     throws XPathException

      Processing Instruction
      Parameters:
        `target` - The PI name. This must be a legal name (it will not be checked).
        `data` - The data portion of the processing instruction
        `locationId` - an integer which can be interpreted using a `LocationProvider` to return information such as line number and system ID. If no location information is available, the value zero is supplied.
        `properties` - Additional information about the PI.
      Throws:
        `XPathException` - if an error occurs

    - #### comment

          public void comment(CharSequence chars,
                     int locationId,
                     int properties)
                       throws XPathException

      Output a comment
      Parameters:
        `chars` - The content of the comment
        `locationId` - an integer which can be interpreted using a `LocationProvider` to return information such as line number and system ID. If no location information is available, the value zero is supplied.
        `properties` - Additional information about the comment.
      Throws:
        `XPathException` - if an error occurs

    - #### setUnparsedEntity

          public void setUnparsedEntity(String name,
                               String uri,
                               String publicId)
                                 throws XPathException

      Set the URI for an unparsed entity in the document.
      Specified by:
        `setUnparsedEntity` in interface `Receiver`
      Overrides:
        `setUnparsedEntity` in class `SequenceReceiver`
      Parameters:
        `name` - The name of the unparsed entity
        `uri` - The system identifier of the unparsed entity
        `publicId` - The public identifier of the unparsed entity
      Throws:
        `XPathException` - if an error occurs

    - #### append

          public void append(Item item,
                    int locationId,
                    int copyNamespaces)
                      throws XPathException

      Append an arbitrary item (node or atomic value) to the output
      Specified by:
        `append` in class `SequenceReceiver`
      Parameters:
        `item` - the item to be appended
        `locationId` - the location of the calling instruction, for diagnostics
        `copyNamespaces` - if the item is an element node, this indicates whether its namespaces need to be copied. Values are `NodeInfo.ALL_NAMESPACES`, `NodeInfo.LOCAL_NAMESPACES`, `NodeInfo.NO_NAMESPACES`
      Throws:
        `XPathException` - if the operation fails

    - #### usesTypeAnnotations

          public boolean usesTypeAnnotations()

      Ask whether this Receiver (or the downstream pipeline) makes any use of the type annotations supplied on element and attribute events
      Returns:
        true if the Receiver makes any use of this information. If false, the caller may supply untyped nodes instead of supplying the type annotation

Copyright (c) 2004-2013 Saxonica Limited. All rights reserved.